Massachusetts, New Hampshire, and Vermont wastewater plants along the Connecticut River are waiting to hear from the Environmental Protection Agency. Even without specifics, managers at the larger plants know they will be required to adjust the amount of nitrogen in their treated wastewater, considerably lowering the levels, potentially at a high cost.

By the end of the year, the Environmental Protection Agency is expected to announce new limits on the amount of nitrogen that wastewater treatment plants in Massachusetts, Vermont, and New Hampshire can release into the Connecticut River.